A wide area network (WAN) is a network which covers a large geographical area, and uses communications circuits and systems to connect participating network nodes. “Wide area” coverage is defined by a number of fixed base stations which are typically distributed geographically over a large area and are connected over a wired network. Often these stations are distributed in such a way that no one station could cover the same geographic area by itself (however this isn't always the reason for such a wide area network). This enables a first mobile wireless radio within the coverage of a first fixed base station to communicate with other (second, third, etc.) mobile wireless radios within the coverage of remote fixed (second, third, etc.) base stations. Other types of units which can be on the wide area network (WAN) are console units—these are units where users can communicate to other console users as well as mobile radio users; however the console connects to the network over a wire rather than wirelessly.
Wireless wide area networks utilize communication technologies such as WIMAX (Worldwide Interoperability for Microwave Access), UMTS (Universal Mobile Telecommunications Service), GPRS (General Packet Radio Service), CDMA (Code division multiple access), GSM (Global System for Mobile communications), CDPD (Cellular Digital Packet Data), HSDPA (High-Speed Downlink Packet Access), 3G (third generation), 4G (fourth generation), and the like, to transfer data.
Within a wide area network, a variety of communication scenarios can co-exist. For example, one use of the wide area network is to enable a group call that allows one mobile radio user to transmit to many mobile radio users who are listening. Other examples of communication scenarios within a wide area network are a private call (e.g., a private call from one mobile radio to another mobile radio), a short data call (e.g. text messaging), and an emergency call. Conventional wide area network topologies use a centralized infrastructure such as a centralized controller within a wide area network to maintain and distribute mobility information of mobile radio users to intended stations. Such distribution of mobility information of a mobile radio user may either occur periodically after the establishment of a group call or a private call or an emergency call. Detrimentally, distributing such mobility information during such calls maximizes the media delay. Further, having a centralized controller to perform the functions of maintaining and distributing mobility information to stations affects the scalability of the wide area network and is susceptible to a single point of failure thereby affecting the entire system.
In addition, in such wide area networks utilizing a centralized controller, a mobile radio user wishing to establish a group call with other mobile radio users within the group must send the media to all the stations within the wide area network, irrespective of whether that particular station is serving a mobile radio user belonging to the group. In this case, the bandwidth is not efficiently utilized as the media is sent to all the stations including those stations which are not serving any mobile radio users belonging to the group. Accordingly, there is a need for a system and method for wide area network (WAN) communication that reduces media delay, eliminates single points of failure, and reduces bandwidth consumption associated with communication between stations as well as from stations to subscribers.
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The apparatus and method components have been represented where appropriate by conventional symbols in the drawings, showing only those specific details that are pertinent to understanding the embodiments of the disclosure so as not to obscure the disclosure with details that will be readily apparent to those of ordinary skill in the art having the benefit of the description herein.